1. Field of the Invention
The present invention relates to a rotary self-propelled type insertion apparatus.
2. Description of the Related Art
Generally, an insertion apparatus such as an endoscope apparatus is inserted into a lumen. Among these types of insertion apparatuses, an insertion apparatus which is called a rotary self-propelled type has been known. The rotary self-propelled type endoscope apparatus is provided, for example, with a rotational housing which is called a spiral tube, etc. in which a spiral-shaped fin is formed on an outer peripheral surface of the insertion section. When the rotating housing is rotated, the fin formed to the rotational housing is brought into contact with an inner wall of a lumen, and generates friction. The insertion section self-propels in an insertion direction or in a removal direction by the friction. For example, Jpn. Pat. Appln. KOKAI Publication No. 2014-064686 provides suggestions regarding these types of self-propelled insertion apparatuses.